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path: root/net/ipv4/inet_timewait_sock.c
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Diffstat (limited to 'net/ipv4/inet_timewait_sock.c')
-rw-r--r--net/ipv4/inet_timewait_sock.c55
1 files changed, 28 insertions, 27 deletions
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index 9bcd8f7234ec..6d592f8555fb 100644
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -87,19 +87,11 @@ static void __inet_twsk_kill(struct inet_timewait_sock *tw,
refcnt += inet_twsk_bind_unhash(tw, hashinfo);
spin_unlock(&bhead->lock);
-#ifdef SOCK_REFCNT_DEBUG
- if (atomic_read(&tw->tw_refcnt) != 1) {
- pr_debug("%s timewait_sock %p refcnt=%d\n",
- tw->tw_prot->name, tw, atomic_read(&tw->tw_refcnt));
- }
-#endif
- while (refcnt) {
- inet_twsk_put(tw);
- refcnt--;
- }
+ BUG_ON(refcnt >= atomic_read(&tw->tw_refcnt));
+ atomic_sub(refcnt, &tw->tw_refcnt);
}
-static noinline void inet_twsk_free(struct inet_timewait_sock *tw)
+void inet_twsk_free(struct inet_timewait_sock *tw)
{
struct module *owner = tw->tw_prot->owner;
twsk_destructor((struct sock *)tw);
@@ -118,6 +110,18 @@ void inet_twsk_put(struct inet_timewait_sock *tw)
}
EXPORT_SYMBOL_GPL(inet_twsk_put);
+static void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw,
+ struct hlist_nulls_head *list)
+{
+ hlist_nulls_add_head_rcu(&tw->tw_node, list);
+}
+
+static void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
+ struct hlist_head *list)
+{
+ hlist_add_head(&tw->tw_bind_node, list);
+}
+
/*
* Enter the time wait state. This is called with locally disabled BH.
* Essentially we whip up a timewait bucket, copy the relevant info into it
@@ -146,26 +150,21 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
spin_lock(lock);
/*
- * Step 2: Hash TW into TIMEWAIT chain.
- * Should be done before removing sk from established chain
- * because readers are lockless and search established first.
+ * Step 2: Hash TW into tcp ehash chain.
+ * Notes :
+ * - tw_refcnt is set to 3 because :
+ * - We have one reference from bhash chain.
+ * - We have one reference from ehash chain.
+ * We can use atomic_set() because prior spin_lock()/spin_unlock()
+ * committed into memory all tw fields.
*/
- inet_twsk_add_node_rcu(tw, &ehead->twchain);
+ atomic_set(&tw->tw_refcnt, 1 + 1 + 1);
+ inet_twsk_add_node_rcu(tw, &ehead->chain);
- /* Step 3: Remove SK from established hash. */
+ /* Step 3: Remove SK from hash chain */
if (__sk_nulls_del_node_init_rcu(sk))
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
- /*
- * Notes :
- * - We initially set tw_refcnt to 0 in inet_twsk_alloc()
- * - We add one reference for the bhash link
- * - We add one reference for the ehash link
- * - We want this refcnt update done before allowing other
- * threads to find this tw in ehash chain.
- */
- atomic_add(1 + 1 + 1, &tw->tw_refcnt);
-
spin_unlock(lock);
}
EXPORT_SYMBOL_GPL(__inet_twsk_hashdance);
@@ -490,7 +489,9 @@ void inet_twsk_purge(struct inet_hashinfo *hashinfo,
restart_rcu:
rcu_read_lock();
restart:
- sk_nulls_for_each_rcu(sk, node, &head->twchain) {
+ sk_nulls_for_each_rcu(sk, node, &head->chain) {
+ if (sk->sk_state != TCP_TIME_WAIT)
+ continue;
tw = inet_twsk(sk);
if ((tw->tw_family != family) ||
atomic_read(&twsk_net(tw)->count))